As is the case for most film criticism media, the subject of spoilers is a long-standing concern on Wittertainment.
Obviously, there are some very famous ones that require no further elaboration. But how much information is revealed on the programme about a film - either by Mark and Simon or by the listeners in emails - is a very sensitive area.
As Mark has explained on air, the rule generally is that anything in the set-up - the basic plot of the film - is ok. Anything that happens in the opening moments of the film - even if it a surprise, such as a car crash (The Lake House being a classic example) - it is usually considered safe to reveal. When a key point to a film is something ambiguous, the phrase "may or may not be" is usually deployed (for example, Gael Garcia Bernal may or may not be the son of William Hurt in The King; the son starts making friends with children "who appear to be, or may be, or perhaps they aren't, imaginary friends" in El Orfanato).
There are exceptions, however. Both Mark and Simon are keen to avoid revealing details that are routinely given away by other press reviews if it is likely to spoil key or exciting moments - such as some of the CGI work in Rogue One: A Star Wars Story. Other times Mark will try and explain things as cryptically as possible, although this does not always work as he has Simon (in his choric role as the voice of the listener) to contend with. One example: when reviewing The Ruins, Mark referred to "necrotising tendrils" to try to avoid giving too much away. This was somewhat undermined when Simon asked "does that mean the plants eat people?"
When reviewing The Mist, Mark revealed it has "the bleakest ending in quite some time" - later changing this to of all time. Simon pondered whether this was that everyone dies, but Mark explained that it was actually worse than that.
Simon got very cross during Mark's review of El Orfanato when Mark restricted himself to saying "the thing happened... and then the thing which really was scary happened."
In the case of Never Let Me Go, Mark felt it would be a spoiler even to reveal what genre the film was in.
During listener correspondence in the Box Office Top 10, Simon audibly redacts spoilers that have been included in listener emails, humming over them or scribbling them out with his pen. However, on occasion he has not actually seen the film in question and it has been the case that he has accidentally revealed rather more than intended. One such instance was with A History Of Violence, which Mark (who considered it, alongside Crash (the Sandra Bullock one), the best film of 2005) had been very cagey about saying much about, other than that Viggo Mortensen would be acknowledged as the new Robert de Niro by 2010. However, Simon's reading an email from one listener saying that the film's plot was ripped off of The Long Kiss Goodnight was enough to prompt complaints from other listeners that it had given the game away.
It is interesting to note however that when listener correspondence gave away the ending of Indiana Jones And The Kingdom Of The Unmemorable Name Made Of Gold, Mark was much less bothered.
Mark has stated that he suffered a torrent of abuse when, during an introduction of the original Ringu on Channel 4, he said "the bit when Sadako comes out of the television set is really scary"; viewers wrote in saying "not after you told us it was going to happen, it wasn't." Mark admitted this was "the most valid criticism" he had received in his career. On the other hand, he did not agree with when one person complained that he had given away too much of Audition by repeating the line "and now for the left leg" ("I'm sorry, but if you can figure out the plot of Audition from the line "and now for the left leg", then you are cleverer than I am.")
Lest it be thought that Mark is solely at fault for giving things away, it was Simon who revealed the Unfortunate Event while filling in some airtime before a horse race. He did argue that no-one listening wth any interest in Harry Potter would be unaware of the precise nature of the Unhappy Event, but listener feedback disagreed. Subsequent efforts to avoid revealing it kept being undermined anyway - first by playing a clip in which Harry and friends discussed Dumbledore's will, and then a couple of weeks after by stand-in Richard Bacon (who had not seen the film - no change there) reading out a listener email that referred to “Dumbledead”.
When the film under discussion is one that is on the end of a Kermodian rant, rather more of the plot tends to be revealed. The famous review of Pirates Of The Caribbean: At World's End contained a key plot point from near the end of the film. He was not exactly coy about the connection between Audrey Tatou and Jesus in The Da Vinci Code either - and he was desperate to talk about the hilarious end of Angels and Demons, only being stopped by Chippy German Michael Stich during a guest appearance at Wimbledon in 2009. The Last Holiday review went one better, flat out revealing whether or not Queen Latifah's character was fatally ill, for which Simon royally took him to task. (SIMON: How much time and effort went into making that film that you've now just spoiled? MARK: Very little).
Mark was intrigued when critics at the screening of Seven Pounds were asked in the press notes not to give away crucial plot details about what the title means once they had seen the film. This intrigue rapidly turned to annoyance, since it was so easily guessable. ("Ever seen Jesus Of Montreal? It's that.") The only mystery was what was the jellyfish there for, and the fact that the whole film kept trying to go, "ooh, isn't this mysterious? What's going on here then? Mmm" really put him off. (He later invited Gary Lightbody of Snow Patrol to guess what happened at the end. It turned out that Lightbody's surname is astonishingly apt).
Also, when a work has been around for a decent period of time in some kind of media and is broadly known, it is felt that there is little to be lost by talking about the end. There were no qualms about revealing the existence and identity of the woman in the attic in Jane Ayre, for example, or the bit at the end of Romeo And Juliet that gets changed in Gnomeo And Juliet. Indeed, Mark suggested that parents with concerns about how their children would deal with The Lion, The Witch And The Wardrobe could tell them in advance that when Aslan is killed, it might not be the end of the story, what with it being a Christian allegory and everything.
On top of that are films that deal with well-known events in world history. Is it a spoiler to say that Apollo 13 makes it back? (It would have been for Wendy Lloyd). Or that the Valkyrie plot doesn't kill Hitler? Or that the Titanic sinks? Simon did in fact (jokingly) tell Mark off for revealing that Victoria marries Albert in The Young Victoria. And the flip side is that when it comes to sport films, Mark has no idea what will happen, which does make it more tense for him - Senna, Rush, Borg Vs McEnroe and Invictus all being movies where Mark has spoken about not knowing how things would work out despite it being common knowledge amongst the wider public.
Sometimes, of course, the films themselves - Wrongteous Kill, for example - come with a TWIST AHOY! alert honking throughout the script, so that regardless of what either or Mark and Simon say, if you can't see it coming, you're really not trying.
When the Wittertainment audience overwhelming demands a discussion of the ending of a popular film - such as The Dark Knight Rises or Rogue One: A Star Wars Story - this is done at end of the podcast and preceded by an official BBC spoiler alert.